The Southern Right Whale (Eubalaena australis)

Mar 05, 2017 Features / Columnists, Interesting Creatures in Guyana

---

The southern right whale (Eubalaena australis) is a baleen whale, one of three species

classified as right whales belonging to the genus Eubalaena. Approximately 10,000 southern right whales are spread throughout the southern part of the Southern Hemisphere.
It is believed that the right whale populations first split because of the joining of North and South America. The rising temperatures at the equator then created a second split, into the northern and southern groups, preventing them from interbreeding.
Like other right whales, the southern right whale is readily distinguished from others by the callosities on its head, a broad back without a dorsal fin, and a long arching mouth that begins above the eye. Its skin is very dark grey or black, occasionally with some white patches on the belly.
The right whale’s callosities appear white due to large colonies of cyamids (whale lice). It is almost indistinguishable from the closely related North Atlantic and the North Pacific right whales, displaying only minor skull differences. It may have fewer callosities on its head than North Atlantic and more on its lower lips than the two northern species.
Biological functions of callosities are unclear although the primal role has been considered to be for protection against predators, and whales’ declines may affect on diversities and quantities of barnacles.
An adult female is 15 m (49 ft) and can weigh up to 47 tonnes (46 long tons; 52 short tons), with the larger records of 17.5–18 m (57–59 ft) in length and 80 tonnes (79 long tons; 88 short tons) or up to 90 tonnes (89 long tons; 99 short tons) in weight, making them slightly smaller than other right whales in the Northern Hemisphere.
The testicles of right whales are likely to be the largest of any animal, each weighing around 500 kg (1,100 lb). This suggests that sperm competition is important in the mating process.
Right whales do not normally cross the warm equatorial waters to connect with the other species and (inter) breed: their thick layers of insulating blubber make it difficult for them to dissipate their internal body heat in tropical waters.
However, based on historical records and unconfirmed sightings in modern periods, E. australis transits might actually occur in equatorial waters. Moreover, a stranding of a 21.3 m (71 feet) long right whale at Gajana, northwestern India in November, 1944 was reported, however, true identity of this animal is unclear.
The proportion and numbers of molten-coloured individuals are notable in this species compared with the other species in the Northern Hemisphere. Some whales remain white even after growing up.
Life span is not clear, although whales seem to reach over 100 years old.
Like other right whales, they are rather active on the water surface, and curious towards human vessels. Southern rights appear to be more active and tend to interact with humans more than the other two northern species. One behaviour unique to the southern right whale, known as tail sailing, is that of using their elevated flukes to catch the wind, remaining in the same position for considerable amount of time.
It appears to be a form of play and is most commonly seen off the coast of Argentina and South Africa. Some other species such as humpback whales are also known to display. Right whales are often seen interacting with other cetaceans, especially humpback whales and dolphins. There have been records of southern rights and humpbacks thought to be involved in mating activities off Mozambique, and along Bahia, Brazil.
They have very strong maternal connections with locations and gene pools they were born in, and especially males may follow patterned migration routes. Calving females are known to return to their ‘birth spots’ at 3-years intervals as the most commonly seen calving intervals are 3 years which may vary from 2 up to 21 years due to multiple factors. Specific congregation areas in the same region may function as for different objectives for whales.
This species has been recognized to nurse unrelated orphans on occasions.
The southern right whale, listed as “endangered” by CITES, is protected by all countries with known breeding populations (Argentina, Australia, Brazil, Chile, New Zealand, South Africa and Uruguay). In Brazil, a federal Environmental Protection Area encompassing some 1,560 km2 (600 sq mi) and 130 km (81 mi) of coastline in Santa Catarina State was established in 2000 to protect the species’ main breeding grounds and promote regulated whale watching.
The southern right whale is listed on Appendix I of the Convention on the Conservation of Migratory Species of Wild Animals (CMS) as this species has been categorized as being in danger of extinction throughout all or a significant proportion of their range. This species is also covered by the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region (Pacific Cetaceans MoU).
A two-year, £740,000 project, led by the British Antarctic Survey began in 2016, to discover why almost 500 young have been washed up on the Valdés Peninsula over the last ten years. The project is funded by the UK’s Department for Environment, Food and Rural Affairs (Defra) and the EU. Possible reasons are a lack of krill in the whale feeding grounds at South Georgia, exposure to toxic algae and attacks by kelp gulls (Larus dominicanus).
(Source: Wikipedia)

---

---